Table 18.1 Nomenclature of bone tumors
• Myeloproliferative disease:
• Protein C deficiency
• Antithrombin III deficiency
• Protein S deficiency
• Activated protein C resistance
• Antiphospholipid antibody
• Oral contraceptive pills
• Sickle cell anemia
• Metastatic cancer
• Liver abscess
• Hydatid cyst
• IVC membrane
• Shock liver
• Viral hepatitis
• Toxic hepatitis
• Alcoholic hepatitis
• Perforated viscus
• Peptic ulcer disease
• Cardiac cirrhosis
• Alcoholic cirrhosis
• Cirrhosis of other etiologies:
Budd-Chiari syndrome (BCS) is the obstruction of hepatic venous blood flow. The site of obstruction may be anywhere from the small central lobar veins of the liver to the proximal inferior vena cava (IVC). Although BCS is frequently caused by thrombosis, extrinsic compression and venous malformations may also cause obstruction. BCS may result in portal hypertension, cirrhosis, and liver failure.
Hepatic vein thrombosis
Hepatic venous outflow obstruction
BCS occurs in patients with myeloproliferative syndrome (especially polycythemia vera), and coagulation disorders with hypercoagulability, in patients taking oral contraceptives, paroxysmal nocturnal hemoglobinuria, antiphospholipid antibody syndrome, pregnancy, infections (amebic abscess and echinococcosis), or tumors (HCC, renal cell carcinoma). Frequently, the cause remains unclear (idiopathic BCS).
EPIDEMIOLOGY & DEMOGRAPHICS
BCS is a rare disorder. Etiology varies with geography. In the U.S., BCS is more commonly associated with myeloproliferative disease, hypercoagulable states, IVC membranes, and tumors.
PHYSICAL FINDINGS & CLINICAL PRESENTATION
Variable according to the degree, location, and acuity of the obstruction.
• Fulminant: Severe abdominal pain, jaundice, hepatomegaly, ascites, acute liver failure, and encephalop-athy. Early recognition and treatment are essential to survival. This presentation is more commonly seen in pregnant women.
• Acute: Abdominal pain, hepatomegaly, and progressive liver dysfunction. Without treatment this presentation of BCS may evolve into the chronic form.
• Chronic: This presentation is the result of chronic portal hypertension with or without cirrhosis; ascites, esophageal varices, splenomegaly, coagulopathy, and encephalopathy.
Investigations show a high protein content in the ascitic fluid and characteristic liver histology with centrizonal congestion, haemorrhage, fibrosis and cirrhosis. Ultrasound, CT or MRI will demonstrate hepatic vein occlusion with diffuse abnormal parenchyma on contrast enhancement. The caudate lobe is spared because of its independent blood supply and venous drainage. There may be compression of the inferior vena cava. Pulsed Doppler sonography or colour Doppler is useful as they show abnormalities of flow in the hepatic vein. Thrombophilia screening is mandatory. Multiple defects of coagulation are found. Thrombosis of the portal vein is present in 2% of patients.
Physical examination, laboratory analysis, and imaging studies
Assessment of liver function:
• Transaminases, prothrombin time, albumin, bilirubin, and platelet count
• Viral hepatitis panel, a-1-antitrypsin, serum iron, transferrin saturation, alkaline phosphatase, ceruloplasmin, toxicology screen, antismooth muscle antibody, antimitochondrial antibody, and double-stranded DNA antibody
Doppler ultrasound is usually sufficient. If this study is technically limited, MRI and CT scan may demonstrate collateral circulation and poor visualization of the hepatic veins. MRI and CT scan may also be able to localize any masses. Venography may be indicated if the diagnosis is still in doubt.
In the acute situation, thrombolytic therapy can be given. Ascites should be treated, as should any underlying cause (e.g. polycythaemia). Congenital webs should be treated radiologically or resected surgically. A transjugular intrahepatic portosystemic shunt (TIPS) is the first treatment of choice as caval compression does not prejudice the efficacy of TIPS. Surgical porto-caval shunts are reserved for those who fail this treatment providing there is no caval obstruction or severe caval compression when a caval stent can be inserted. Liver transplantation is the treatment of choice for chronic Budd-Chiari syndrome and for the fulminant form. Lifelong anticoagulation is mandatory following TIPS and transplantation.
ACUTE GENERAL Rx
• Supportive measures
• Liver transplant may be indicated for fulminant BCS
• Shunting, stenting, or angioplasty to decompress the portal circulation may be indicated for acute BCS in patients in stable condition
• Thrombolytic therapy can also be used to decompress the portal circulation
• Chronic anticoagulation may be needed to maintain shunt patency or in patients with thrombotic BCS
• Liver transplantation
• Shunt thrombosis is a common complication
Prognosis is dependent on time to recognition and treatment, etiology, acuity, and the type of intervention.